Source : Webster's Revised Unabridged Dictionary (1913)

Spiculum \Spic"u*lum\, n.; pl. {Spicula}. [L., a little point.]
   (Zo["o]l.)
   Same as {Spicule}.

Source : WordNet®

spiculum
     n : small pointed structure serving as a skeletal element in
         various marine and freshwater invertebrates e.g. sponges
         and corals [syn: {spicule}]
     [also: {spicula} (pl)]